One. I was called up one other time, but rejected when they found I was a Ph.D. and actuary (knowledgable in pension laws.)
I did say “generally”, and I was certainly exaggerating for emphasis, but watch the exclusion process sometime.
The one jury I was on, after about fifteen minutes of testimony by one side (the other side didn’t show up), the judge told us we must decide the case this-and-so. One of the jurors asked, “Why?” and the judge said, “You’re off the jury,” and pulled in an alternate from the jury room (who hadn’t even heard the testimony, such as it was) who would decide as the judge instructed. That’s why my comment, the jury must do exactly as the judge tells them, asking “Why?” is a capital offense.
However, just because I didn’t serve on juries doesn’t mean I’m not familiar with them. I dealt some with expert witness testimony (not myself, but helping a colleague prepare), and I have a couple lawyers as friends and family… and likely future family-member in lawschool.
They all tell me pretty much the same thing: Lawyers generally want jurors who will think the way the lawyers tell them to, not who will think for themselves. Financial cases are the worst, of course, anyone with financial knowledge (which tends to mean math skills) gets kicked off pretty quickly.
I’m not saying this is unfair – if both sides have equally skillful lawyers, then it’s a contest of wits between the lawyers. I think that’s a helluva way to run a justice system. It’s not much better than letting two knights fight it out, and the one who is the most skillful fighter wins, God (and therefore Justice) was on that one’s side. We’ve replaced the knights with lawyers, and the one who is the best speech-maker wins, and the Jury (and therefore Justice) was on that one’s side.
Yes, you’re correct, they only have so many pre-emptory discharges. And of course, they’d never come out and say, “We don’t want this one, she’s too smart” – that would be not very politic. And potentially disastrous if that information got to the jurors who were selected: “Oh, he thinks I’m not so smart, eh?” So, I’m not saying that every single person on a jury is stupid, but I’m saying that the average intelligence of the average jury is way below that of the general population.
Also, of course, there’s the other side to it: top businesspeople and bright people who don’t want to waste time on the jury can find ways to get out of it. So the sample basis is biased, right from the start.